Gauging device for hinge seat router bit



June 11, 1957 w. B. ZERN GAUGING DEVICE FOR HINGE SEAT ROUTER BIT Filed June 3, 1955 llb Unied [S ws P ten GAUGING DEVICE FUR HINGE SEAT ROUTER BIT Warren B. Zern, Montgomery County, near Pottstown, Pa. Application June 3, 1955, Serial No. 512,968

10 Claims. (Cl. 144-27 This invention relates to a gauging device for predetermining the setting of a router bit to control the routing depth of the bit, and has for an object the provision of an improved gauging device particularly suited for use in connection with woodworking apparatus for routing hinge seats in a jamb and in the door as disclosed in my Patents Nos. 2,355,603 and 2,427,081 and Schwarzer Patent No. 2,605,790, assigned to me, and in my copending application Serial No. 455,890, filed September 14, 1954.

The woodworking apparatus disclosed in the abovementioned patents and application utilize various types of template assemblies to aid in quickly and accurately routing hinge seats in jambs and doors. Such devices are adapted for the installation of diiferent sizes of hinges, and thus it becomes necessary for the operator to be able to check his work when he has changed from one setting of the apparatus to another to insure that no error has been made. The importance of such check by the operator is quite apparent, as the foregoing woodworking apparatus is particularly suited for use in prefabricating doors and jambs for precut building construction. Thus it is not unusual to cut many doors and jambs in succession, and if an error had been made by the operator in adjusting the woodworking apparatus, a large amount of material might be spoiled if the operator could notcheck his work to insure that no error had been made in adjustment. I

In accordance with the present invention thereis pro-. vided a gauging device whereby the operator may predetermine the setting of a router bit to control the routing depth thereof in accordance with the particular operation to be performed, such as routing hinge seats in a door and jamb. It is very important that the depth of the hinge. seat'be accurately cut, as any error in depth will be doubled when the door and jamb are assembled for the reason that the seats in the door and jamb are cut concurrently and to the, same depth with woodworking apparatus for the foregoing type. $5 of an inch are too great to provide for a good fit of the hinge on the door and jamb.

More specifically, the present invention provides a gauging device for predetermining the setting of a router bit relative to the base plate of the router to control the routing depth of the bit comprising a central body portion having adjacent one end a pair of supporting arms projecting at opposite sides therefrom. The body portion has an opening extending therethrough, the axis of the opening being perpendicular to the common plane of the outer surfaces of the pair of arms. There is a plunger reciprocable Within the opening, the plunger having a length less than the distance measured along the axis of the opening from the common plane to the other end of the body portion by a predetermined amount related to the selected routing depth whereby the router bit may be inserted into the body opening with'thc surfaces of the pair of arms in a common plane resting on the base plate of the router for relative adjustment between the router bit and the Errors as. small as.

base plate to bring the elevation of the end of the plunger into alignment with the other end of the body portion For a more detailed disclosure of the invention and for further objects and advantages thereof, reference is to be had to the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a sideelevation of the novel gauging device supported on the base plate of a router in its normal position for gauging the setting of the router bit;

Fig. 2 is an enlarged side elevation of the gauging device shownin Fig. 1 taken from the rear and with the device inverted;

Fig. 3 is a top plan view looking along the lines 3-3 in Fig. 2;

Fig. 4 is a rear elevation of the device as shown in Fig. 2; b

Fig. 5 is an end elevation looking along the lines 5-5 in Fig. 3 a showing in section and fractional view of the router and its locking key; and

' Fig. 6 is a sectional view taken in Fig. 3.

Referring to the drawings, the novel gauging device 10 has been shown in Fig. 1 as supported on the base plate 53 of a conventional router 51 such, for example, as of the type illustrated in the aforesaid Patent No. 2,605,790 and identified by the same reference characters. In that along the lines 6-6 patent at Fig. 21 it is shown how the router 51 is used in connection with a template assembly with the base plate 53 adapted to engage the upper fiat surface of a template assembly. The router bit 52 extends through a stationary.

guide bushing 54 which is adapted to engage the edges of the opening in the template accurately to locate the router 51 during its movement through the open area of the template. The router 51 is normally used in a position inverted from that shown in Fig. 1 of this application. As described in the aforesaid Patent No. 2,605,- 790, the router 51 is lowered into position with the flat surface of its base or guide plate 53 placed against the upper fiat surface of a template. The router 51 is then briskly moved about the edges of the opening in the template, and it is then moved back and forth until all of the wood in the door and the jamb within that area has been removed to a predetermined depth to form the completed hinge seats. In determining the depth of setting for the router bit 52, allowance must be made for the depth of the template assembly in addition to the thickness of the hinge being installed. The novel gauge 10.0f this application and now to be described in detail determines such depth of setting for the router bit.

7 The gauging device 10 comprises a central body member or portion 11 having adjacent one end thereof a pair of supporting arms 12 and 13 projecting at opposite sides therefrom, Figs. 2-4. The body portion 11 is provided with an opening 14 extending therethrough, the axis of the opening being perpendicular to the common plane of the outer surfaces 12a and 13a respectively of the pair of arms 12 and 13. Reciprocable within the opening 14 is a plunger 16. The plunger 16 is shorter than the depth of the opening 14 and the length of the plunger is less than the distance measured along the axis of the opening 14 from the common plane of surfaces 12a and 13a to the other end of body portion 11 by a predetermined amount related to the selected routing depth and allowing for the depth of the template assembly with which the router 51 is to .be used. The. plunger. 16 is mounted for limited movement axially of opening 14. The plunger 16, as shown in Figs. and 6, is provided with a slot or groove 16:: having spaced shoulders between which passes a pin 17 which is carried by the body portion 11.: The pin 17 holds the plunger 16 within the opening 14 for limited reciprocation, and the over-all length of the plunger 16 with relation to the over-all length of opening 14 will determine the. proper setting of router bit 52. The proper setting of the router bit is determined when the end of plunger 16 is flush with the end 11b of the body member 11.

With this arrangement, Fig. 1, the router bit 52 may be inserted into the opening 14 in body portion 11 with the surfaces12a and 13a of the pair of arms 12 and13 resting on the base .plate 53 of the router 51. l The router 51 has been illustrated as ofthe type including a power or motor driven member 55, the outer surface of which threadedly carries a housing 56 which in turn islprov'ided with the base plate 53 and handles 57 formoving the router over the template assembly. The depth of cut of the router bit 52 may be changed by locating outerfhousing 56 relative to the router member 55 and thus changing the distance that the bit 52 projects beyond the outer surface of base plate 53. By locating member 56 .relative to member 55, the routerbit 52 may be adjusted relative to the base plate 53 to bring the elevation of the top of plunger 16 into alignment with the adjacent end 11a of the body portion 11, such alignment being determined by the sense of touch of the operator. After the router has been properly adjusted as determined by the gauging device 10, the two sections 55 and 5610f the router 51 may be locked with respect to each other by means of the locking screw member 58 provided on the router; To facilitate this locking operation, the ganging device is provided .with a key slot 19 cut in the side of body portion 11 and adapted to fit the router locking key 58 as shown in Figs. 1 and 5.

The base plate or guide plate 53 on the router may be formed from any suitable material such, for example, as pressed wood or hard board or the like. Some of these materials have a greater tendency to wear than others, and it has been found that due to the engagement of the base plate 53 with the upper surface of the template assembly .thewear on the base plate is predominantly in an area intermediate the inner and outer edges of the base plate, that is, between the edge adjacent the router bit 52 and the outer periphery of the plate 53. For that reason it is preferable that the. spaced arms 12 and 13 of the gauging device .10 be undercut at Hz: intermediate the surfaces 12a and 13a so that the latter surfaces may engage the worn area and insure that the router bit 52 will be gauged for the proper setting by the device 10.

After the complementary hinge seats have been cutin the door and its corresponding jamb, it is preferable for the operator to double. check his work by measuring the combined depths of the hinge seat in the door and the hinge seat in the jamb, as this dimension will determine whether or not the door will hang properly when installed. To simulate this condition, the hinge seat in the door and the hinge seat in the jamb are placed together with the hinge seats in overlying relation. To check the combined depths of the hinge seats in the door and the jamb, one arm of the gauging device 10, such as arm 12, is provided with a beveled surface 12b opposite the outer surface 12a for gauging different hinge seat depths corresponding to diiferent hinge sizes. The beveled surface 1211 may be provided with any suitable indicating means, such as scale markings corresponding to different hinge sizes, or the arm 12 may be provided with shoulders, such as shoulders 20 and 21, such shoulders being disposed along the side of the arm 12 at locations corresponding to the combined depths of binge seats in 4 the jamb and door. may be positioned along the sloping surface 12b at a position corresponding to the correct combined depths of binge seats for a standard size hinge, such as a three and one-half inches by three and one-half inches hinge and the shoulder 21 may be disposed at the proper location to gauge the combined depths of hinge seats in a jamb and door for another size hinge, such as a four inches by four inches hinge. These are two quite commonly used hinge sizes and, of course, it is to be understood that additional indicating means for gauging other hinge sizes may also be provided on the arm 12 if desired.

Since the two foregoing hinge sizes are quite commonly used today, it is preferable that the gauging device 10 be adapted to gauge for cutting hinge seats for either hinge size. Accordingly, as may be seen in Fig. 3 5 and 6, the body portion 11 may be provided with a second opening 25 within which a plunger 26 is adapted to reciprocate. The plunger26 is provided with a slot or groove 26a in the side thereof through which passes a pin 27 extending into the walls of body member 11. It will be noted that the over-all length of plunger 26 is different from that of plunger 16, such difference corresponding to the difference in thicknesses of the two sizes of hinge plates which in turn determines the depth of hinge seats. to be cut in the jamb and door. For convenience the length of the plunger 26 is selected to correspond to the hinge .size previously referred to in connection with the gauge shoulder 21 on arm 12. Thus, when the router bit 52 is set in accordance with the alignment of the end of plunger 26 with the adjacent surface 11b of body member .11, the resulting hinge seats that are cut with the router may be checked as to their combined depths by inserting the arm 12 into the overlying hinge seats in the manner previously described. If the router has been properly adjusted, the arm '12 should be capable of extending into the overlying hinge seats a distance corresponding to the position of shoulder 21 on arm 12.

To further check the work performed with woodworking apparatus of the type disclosed in the aforesaid patents and application, the gauging device 10 is provided with further novel features. For example, to check the width of the hinge seats after they have been cut by the router, the surface 11c of the body portion 11, Figs. 4 and 5, may be disposed transversely of the hinge seats and the surface 11c provided with markings, as at 30 and 31, corresponding to the correct width of the aforementioned common hinge sizes. This gauging feature is important as in some of the above-mentioned woodworking jigs the template assemblies are provided with one single opening corresponding to the combined hinge seats in a door and jam. Thus, if the door was not of uniform thickness throughout its length, such non-uniformity might cause the template assembly to be improperly positioned during the routing operation, thus resulting in a larger hinge seat being cut in the jamb than in the door or vice versa. This would not be readily apparent to the operator of the woodworking apparatus without gauging the hinge widths in the foregoing manner.

As discussed in the aforesaid patents and copending application, it is quite common today to use either doors that have a square edge for receiving the hinge seats or a beveled edge. The customary bevel is generally in the order of three degrees. This means that the finished hinge seat will taper at an angle of approximately three degrees from the open end of the hinge seat to the rear. The taper is provided to prevent the door from being hinge-bound and provides the necessary clearance in the event that the screws which are used in the hinge should not accurately fit in the beveled holes provided therefor, this being a circumstance that frequently arises when the screws are inserted at an angle with respect For example, the shoulder 20 to the holes. In order that an operator may readily determine whether he is working on square edged doors or bevel edged doors and if the doors are properly beveled, the surface 110 as shown in Figs. 5 and 6 is beveled with respect to the vertical plane at an angle of approximately three degrees and thus at an angle of approximately eighty-seven degrees with respect to the plane of surfaces 12a and 13a. By placing the surfaces 12a and 13a against the side of the door, the surface 11c may be aligned with this hinge-receiving edge of the door and the operator will at once be able to tell if the door is a bevel edged door as the edge of the door and the surface 110 of gauge will be in a common plane.

While the primary function of the spaced arms 12 and 13 is to provide the necessary stability for the gauge as well as the locating surfaces 12:: and 13a for use in the gauging of the router bit setting, such arms may also have additional functions as above described in connection with the additional functions for arm 12. Arm l3 likewise may have additional functions related to gauging the work for proper hanging of doors. As described in the aforementioned patents and copending application, the locating of the hinge jigs in relation to the hingereceiving edge of the door and the hinge-receiving surface of the jarnb is frequently accomplished by using the dado groove in the jarnb as the reference. In such arrangements the woodworking apparatus or jigs preferably are provided with jarnb locators such, for example, as illustrated in Fig. 6 of the aforesaid Patent No. 2,605,790, with the jarnb locator being adapted to be disposed within the dado adjacent the head end of the jamb. It is important that the dado grooves in each of the side jambs be cut to the proper depth as the combined depths of the dado grooves plus the width of the door plus the desired clearance between the door and side jambs determines the length of the head jamb. Thus, the combined depth of the two dado grooves with the two side jambs held together is an important checking point. Accordingly, the width of the arm 13, Figs. 3 and 5, preferably corresponds to the double depth of a standard dado for gauging the combined depths of the dado grooves in the side jambs. The jambs are held together face to face and the arm 13 is inserted into the opening formed by the overlying dado grooves in the two jambs. Likewise, the thickness of the arm 13 as shown in Figs. 2 and 5 may be made to correspond to the depth of a single dado groove for gauging the depth of the dado in a single side jamb, and thus the rectangular cross-sectional area of arm 13 as shown in Fig. 5 will have a width twice as long as its thickness.

From the foregoing it will be seen that the novel gauging device 10 of the present application permits an operator quickly and accurately to gauge and check the work that he has performed with woodworking apparatus of the type disclosed and claimed in the aforementioned patents and copending application and thus eliminates the possibility of spoiling a substantial amount of material such as doors and jambs through improper setting of the woodworking apparatus.

While a preferred embodiment of this invention has been illustrated, it is to be understood that other modifications thereof may be made within the scope of the appended claims.

What is claimed is:

1. A gauging device for predetermining the setting of a router bit relative to the base plate of the router to control the routing depth of the bit comprising a central body portion having adjacent one end a pair of supporting arms projecting at opposite sides therefrom, said body portion having an opening extending therethrough the axis of which is perpendicular to the common plane of the outer surfaces of said pair of arms at said one end of said body portion, and a plunger reciprocable within said opening, said plunger having a length less than the distance measured along the axis of said opening from said common plane to the other end of said body portion by a predetermined amount related to the selected routing depth whereby the router bit may be inserted into said body opening with the surfaces of said pair of arms in a common plane resting on the base plate of the router for relative adjustment between the router bit and the base plate to bring the elevation of the end of said plunger into alignment with said other end of said body portion as determined by the sense of touch preparatory to locking the base plate in said predetermined setting.

2. A gauging device accordingto claim 1 including stop means carried by said body portion and 'engageable with said plunger to maintain said plunger within said opening for reciprocation within predetermined limits.

3. A gauging device according to claim 2 wherein said stop means comprises a pin inserted in the body portion and projecting into said opening and said plunger has a pair of spaced shoulders one disposed on each side of said pin to limit the axial movement of the plunger within said opening.

4. A gauging device according to claim 1 wherein said plunger controls the adjustment of the router bit for cutting complementary hinge seats in a door and its corresponding jamb and one of said supporting arms has a thickness equal to double the depth of one of said hinge seats for gauging the combined depth of the hinge seat in the door and the hinge seat in the jarnb when said door and jamb are placed together with said hinge seats in overlying relation simulating the conditions existing when said door and jamb are installed.

5. A gauging device according to claim 4 wherein said one supporting arm has a beveled surface opposite said outer surface for gauging different hinge seat depths corresponding to different hinge sizes and said body portion includes a second opening therethrough parallel to said first opening and a second plunger is provided for reciprocation in said second opening within different limits from those of said first-named plunger to gauge the setting of the router bit for the cutting of hinge seats corresponding to a different size hinge.

6. A gauging device according to claim 1 wherein said body portion includes a slot therein adapted to receive and adjust means for locking and unlocking the router base plate with respect to the router frame to control relative movement therebetween.

7. A gauging device according to claim 1 wherein'one surface of said body portion is inclined at an angle of about eighty-seven degrees with respect to the common plane of said outer surfaces of said pair of supporting arms for gauging the bevel on the door edge preparatory to routing hinge seats therein.

8. A gauging device according to claim 5 wherein said body portion extends to one side of said pair of supporting arms a distance at least as great as the width of the maximum hinge seat as gauged by either of said plungers and one surface of said body portion is provided with means to identify and gauge the hinge seat widths corresponding to the standard hinge seat widths utilized with the hinge seat depths as determined by either of said plungers.

9. A gauging device according to claim 4 wherein the other arm of said pair of arms has a rectangular crosssectional area with the width being twice as long as its thickness and corresponding respectively in dimension to the double and single standard depth of dado grooves for gauging the dado in a door jamb.

10. A gauging device according to claim 1 wherein the common plane of the outer surfaces of said pair of arms is spaced to one side of the remainder of said arms and said body portion whereby said supporting arms engage the base plate of the router at locations of maximum wear and are displaced from the area of the base plate immediately surrounding the router bit.

No references cited. 

